LCM of 640, 420, 665, 390, 645
Reviewed By : Rajashekhar Valipishetty
Last Updated at : Mar 29,2023
Find the LCM of 640, 420, 665, 390, 645 with the LCM of Two or More Numbers Calculator. Here we are teaching you two different methods through which you can calculate the LCM of 640, 420, 665, 390, 645. So, keep reading to learn more.
Given numbers are 640,420,665,390,645
The least common multiple of numbers can be find using the prime factorization method or LCM formula.
The LCM of 640,420,665,390,645 is 142746240.
Find LCM of 640,420,665,390,645 with Prime Factorization
| 2 | 640, 420, 665, 390, 645 |
| 2 | 320, 210, 665, 195, 645 |
| 3 | 160, 105, 665, 195, 645 |
| 5 | 160, 35, 665, 65, 215 |
| 7 | 32, 7, 133, 13, 43 |
| 32, 1, 19, 13, 43 |
Multiply the prime numbers at the bottom and the left side.
2 x 2 x 3 x 5 x 7 x 32 x 1 x 19 x 13 x 43 = 142746240
Therefore, the lowest common multiple of 640,420,665,390,645 is 142746240.
LCM formula is LCM(a1, a2, an) = (a1 x a2 x an)/{GCF(a1 x a2 x an) x common factors}
Firstly, we have to find the product of all the numbers.
640 x 420 x 665 x 390 x 645 = 44965065600000
Then, let us find the GCF of these five numbers. To do so, we have to list down the factors for each number and choose the highest factor that is in all of the lists.
640 : 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 128, 160, 320, 640
420 : 1, 2, 3, 4, 5, 6, 7, 10, 12, 14, 15, 20, 21, 28, 30, 35, 42, 60, 70, 84, 105, 140, 210, 420
665 : 1, 5, 7, 19, 35, 95, 133, 665
390 : 1, 2, 3, 5, 6, 10, 13, 15, 26, 30, 39, 65, 78, 130, 195, 390
645 : 1, 3, 5, 15, 43, 129, 215, 645
5 is the greatest number that appears in all the lists. Therefore, we can determine that the GCF of 640,420,665,390,645, is 5.
Now, the common factors can be found like this.
640:2x 2x 2x 2x 2x 2x 2x 5
420:2x 2x 3x 5x 7
665:5x 7x 19
390:2x 3x 5x 13
645:3x 5x 43
From this, we can see that the common factors because they appear for more than two numbers. So, just multiply them all together.
2x 2x 2x 3x 3x 5x 5x 5x 7 = 63000
Therefore, the value for common factors is 63000.
Now that we have all the elements of the formula, we can plug them in to calculate the LCM.
LCM(a1, a2, an) = (a1 x a2 x an)/{GCF(a1 x a2 x an) x common factors}
LCM = 44965065600000/(5x63000)
LCM = 44965065600000/315000
LCM = 142746240
Thus, we can understand that the LCM of 640,420,665,390,645 is 142746240.
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FAQs on LCM of 640, 420, 665, 390, 645
1. What is the LCM of 640, 420, 665, 390, 645?
Answer: LCM of 640, 420, 665, 390, 645 is 142746240.
2. How to calculate the LCM of 640, 420, 665, 390, 645?
The LCM can be found using two methods. You can either use the LCM formula or the prime factorization method to calculate the LCM of 640, 420, 665, 390, 645.
3. What is the LCM formula?
The LCM formula is LCM(a1, a2, an) = (a1 x a2 x an)/{GCF(a1 x a2 x an) x common factors}.